Twist-drill-grinding attachment.



J. S. WINGRANTZ.

TWIST DRILL GRINDING ATTACHMENT.

APPLICATION FILED mums, 1914.

1 106 692. Patented Aug.11,1914,

2 SHEETSSHEET l.

WITNESSES INVENTOR .I. S. WINORANTZ. TWIST DRILL GRINDING ATTACHMENT.

APPLICATION FILED JAN.23, 1914.

1,106,692. Patented Aug. 11,1914

2 SHEETS-SHEET 2 WITNESSES of drill,

r a are. let.

T0 S. WINCRANTZ, 0E PITTSBURGH, PENNSYLVANIA, ASSIGNOR T0 SAMUEL S.

' NEWMAN, 0F PITTSBURGH, PENNSYLVANIA.

. Specification of Letters Patent.

Patented ding. 111, 1914i.

Application filed January 23, 1914. Serial No. 813,88?.

ance of the point or end of the drill; the

provision of an improved arrangement wherein the angle of the axis ofthe drill may be varied with respect to the plane of rotation of thegrinding wheel, to provide for the cuttingof the ends of the drills atvarying angles, without shifting the position of the axis of rotation ofthe drill carrier, which arrangement permits the shift ing of thesurface being ground across the" grinding surface of the wheel; theprovision of a. sto or support for the rear end of the drill, a apted toproperly engage all sizes and one that is secure against accidentalmovement; and the provision of a construction adapted to handle drillshaving any number of grooves. One embodiment of the invention isillustrated in'the accompanying drawing wherein ig. 1 is a plan view ofa grinding machine with my improved attachment applied thereto, Fig. 2is a partial side elevation of the construction shown in. Fig. 1, Fig. 3is an enlarged section on the line TH-Hl of Fig. 1, Fig. 4 is anenlarged plan view of a portion of the attachment,

with some of the parts thereof in section,

and Fig. 5 isan end elevation of a portion of the apparatus asillustrated in Fig. 4.

Referring first to Figs. 1 and 2, 1 is a grinding wheel drivenfrom thehandle 2 by means of a gearing inclosed in the casing 3. The! support orbracket 4 is carried in the socket 5 and removably held in positiontherein by means of the thumbscrew 6. The bracket 4 is provided at itsend with. an upturned portion? (Fig. 5) having integral therewiththesleeve 8. Mounted rotatablv in the sleeve 8 is an eccentric sleeve 9(Fig.

4), which sleeve 9 may be clamped against rotary movement by means ofthe set screw 10. A pivot rod 11 extends through the sleeve 9, and thisrod may be adjusted toward and from the axis of rotation of the grindingwheel, by means of the eccentric sleeve 9, which sleeve is provided witha handle 12 to facilitate its convenient rotatlon.

The pivot rod 11 is provided with a head '13 through which is aperforation for the reception of the clamping screw 14. The block 15which su ports the carrier trough 16 is provided wit a perforated flange17 opposing the head 13 of the pivot rod, the head 13 having itsperforation screw threaded to engage the screw threads on the clampingscrew 14, so that the parts may be held fixedly in any desired positionof relative adjustment. If desired, the member 13 may be provided with apin 17 adapted to fit in recesses in the lower face of the flange 17,thus giving additional security to the adjustments and positively fixingthe relative position of the two parts, the recesses being positioned soas to give certain grinding angles for the points of the drill.

lit will be seen that by means of the foregoing construction anadjustment of the axis of the drill being ground, with respect to theplane of rotation of the grinding wheel is secured, thus enabling theattachment to be used to grind difierent an les upon the ends of thedrill. It will also be noted that the adjustment is secured withoutaltering the position of the pivot rod 11, such pivot rod occupying aposition at substantially right angles to the plane of rotation of the rgrinding wheel. The pivot rod 11 is slidably mounted in its sleeve 9 sothat when desired in the grinding operation, the drill carrier can bemoved so as to carry the end of the drill across the face of thegrinding wheel. The entire face of the grinding wheel can thus beutilized, and it will be seen that this would not be the case if thepivot rod 11 wereshifted from its position in parallelism with the axis18 of the grinding wheel (Fig. 1). it is therefore a distinct advantageto have the drill carrier adjustable around the vertical axis 14,without changing the position of the pivot rod 11 as is done 1nsome-prior constructions wherein the sleeve which carries the pivot rodis adfjustable around a vertical axis. slide 11 tendi having a fork 11adapted to engage a groove 11 prevents accidental withdrawal of the rod11.

The trough which carries the drill 19' consists of a pair of platessecured in the block 15, the trough thus formed being substantiallyV-shaped in cross section as indicated 1n Fig. 3. In order to positionthe drill the lip or plate 20 is provided (Fig. 5) which engages one ofthe grooves of the drill at the end thereof, such lip also serving toprevent rotary movement of the drill during the grinding operation. Thedrill is held securely in position during the grinding operation, bymeans of the c amp arm 21, such clamp arm being pivoted to the block 15at 22 (Fig. 5), and being operated by means of the pivoted rod 23carrying the wing nut 24:. The drill is positioned longitudinally 0f thetrough by means of the block 25 (Figs. 1 and 3), such block beingprovided with a V-shaped groove to slidably receive the trough 16 andhaving a set screw 26 for locking the block in position. -Exforwardlyfrom the block 25 is an extension or stem 27 provided at its front endwith a stop plate 28. This stop plate 28 has a flat face for engagingthe rear end of the drill, and itsedges fit down into the groove of thetrough and engage the inner surfaces thereof. It will be seen that thisplate will properly engage drills of all sizes. The provision of theextension 27 whereby the plate 28 is gotten away from the block 25 isalso advantageous inasmuch as the de- 'vice is held very securelyagainst rocking or wabbling mbvement, due to the fact that the points ofsupport upon the trough are widely separated, and due to the" extendedV-shaped bearing secured between the device and the trough. i

- Another feature of construction of considerable importance, isillustrated in Fig. 5, and relates to the upward inclination given tothe axis of the pivot rod 11. This axis is inclined slightly upward withrespect to the axis of rotation of the' inding wheel.

I This is indicated graphica ly in Fig. 5

wherein the line 29 indicates the horizontal plane in which the axis ofrotation 18 (Fig.

the line 30 indicates the axis of the pivot rod 11. The angle betweenthese lines is preferably between three and four degrees,

and its purpose is to secure the. necessary clearance at-the point ofthedrill. The cutting edges-431 and 32 (Fig. 5), when the 61111 is inoperation should'be in contact with the work, while the surfaces at andb between the lines 31 and 33 and 32 and 34 should be clear of the'work, and the inclining of theaxis of thepivot rod upward asheretofore. described secures a -cut by the grinding wheel, this desiredclearance.

point of the drill.

In the grinding of drills having four grooves instead of two the swingof the drill carrier must be limited, and in order to secure this resultthe stop-35 shown in Fig. 2 is employed. This stop is held removably inplace by means of a screw 36 and serves to limit the movement of thecarrier, positively stopping it when it reaches the position indicatedin Fig. 2, with the axis of the drill substantially radial with respectto the grinding wheel. By the use of this at tachment it is possible touse the one mechanism with either two groove or four groove drills, theattachment bein removed when idt ieldesired to grind the ordlnary twogroove The operation of the device is as follows. The drill is placed in-the trough and moved alon until its end engages the surface of the grining wheel, the stop plate 28 at this time being in engagement with therear end of the drill. The thumbscrew 26 is then operated to secure thestop plate 28 in position, and the clamping member 21 is screwed downinto positlon by means of the wing nut 24 (Fig; 5). At this. time thehandle 12 of the adjusting sleeve 9 is in the position illustrated inFig. 2.- After the grindihg wheel hasbeen started the handle 12 isrotated in a counter clockwise direction until the operator is satisfiedthat a sufficient amount of metal has been removed from the loosened andthe drillrotate'd-180". to grind the other lip of the drill, the member20 serving to position the drill in both of its positions. After thedrill has been adjusted .to thisnew position, the grinding operation isrepeated as heretofore described.

' What I claimis:

1. The combination in an attachment foruse with a disk grinding machine,of a support for the attachment, and a-drill carrier mounted forrotation on anaxis transverse The clamp '21 is then- .a short distance,and the set screw 10 op- 2. The combination in an attachment for 1 usewith a diskgrinding machine, of a sup port for the attachment, and adrill carrier mounted for. rotation on an axis transverse to the planeof rotation of the grinding wheel and positioned-so as to bring thedrill in engagement with the edge surface of the wheel, the axis ofrotation of the wheel and carrier lying in substantially parallel planesbut with one axis inclined with respect to g the other.

carrier lying in substantially parallel vertical planes with the axis ofthe wheel substantially horizontal and the axis of the carrier as itapproaches the plane of rotation of the wheel inclined upwardly.

4:. The combination in an attachment for 7 use with a disk grindingmachine, of a supportfor the attachment, a drill carriermounted forrotation on an axis transverse to the plane of rotation of the grindingwheeland positioned so as to bring the drill in engagement with the edgesurface of the wheel, and a movable stop which when in operativeposition limits the'normal swing of the carrier. 4 w

5. The combination in an attachment for use with a disk grindingmachine, of a support for the attachment, a drill carrier mounted forrotation on an axis transverse to the plane of rotation of the grindingwheel and positioned so as to brin the drill in engagement with the ed esur ace of. the wheel, an-eccentric sleeve or adjusting the drillcarrier toward the wheel as the grinding progresses, an operating handlefor the sleeve and means for clamping the eccentric sleeve in anydesired position of adjustment.

6. ln combination in an attachment for use with a grinding wheel, asupport for the attachment, a drill carrier, a pivot rod supporting thecarrier, a sleeve mounted rotatably on the support and carryingeccentrically thereon the pivot rod, a handle for adjusting the sleeveand a set screw for clamping the sleeve in position.

7. In combination in a drill carrier for a grinding machine, a troughV-shaped in cross section for supporting the drill, a block on thetrough with a V-shaped groove therein fitting the trough slidably, aclamping means for securing the block against move ment along thetrough, an extension projecting forwardly from theblock, and a plateatthe front end of the extension having a substantially flat face andhaving its lower portion of V shape to fit the interior of, the trough.

8. The combination in an attachment for I use with a disk grindingmachine, of a support for-the attachment, and a drill carrier having adrill supportin trough V-shape in cross-section and mounted for rotationon an axis transverse to the plane of rotation of the grinding wheel andpositioned so as to bring the drill into engagement with the edgesurface of the wheel, the said axis of rotation being inclined so thatsuch axis extended passes above the line of juncture of the sides of thetrough.

Inv timony whereof I have hereunto signed my name in the presence of thetwo subscribed witnesses. 7

JOHN S. WINCRANTZ. Witnesses:

JAMES C. BRADLEY, Ancnwon'rn MARTDI.

